The problem with too many layers of management is mainly that they stop doing what they should do. Making decisions.
The lowest management layer cannot make any decisions alone, otherwise the next layer would have no reason to exist. The next layer might even have to hand over the decision to one layer above. Up there no one really understands the decision that needs to be made because they are too far away from the actual impact. The result is that the decision is not made at all. Instead they procrastinate by asking for more details about the decision and the options.
If you have only one layer you get a decision very fast.
The lowest management layer cannot make any decisions alone, otherwise the next layer would have no reason to exist. The next layer might even have to hand over the decision to one layer above. Up there no one really understands the decision that needs to be made because they are too far away from the actual impact. The result is that the decision is not made at all. Instead they procrastinate by asking for more details about the decision and the options.
If you have only one layer you get a decision very fast.